The present invention is generally related to off-road vehicles, and, more particularly, to silencing equipment as may be used in an air-cooling assembly for electrical devices onboard an off-road vehicle.
Large off-road vehicles, such as purveyed by Komatsu America Corporation, may be powered by a diesel-electric drive system, such as provided by the assignee of the present invention. The drive wheels of such vehicles may be powered by electric traction motors, which in turn receive electrical power from a diesel-electric generating set. It is known to utilize the drive wheel motors for these vehicles in a braking mode of operation wherein the motors function as electrical generators for retarding the forward progress of the vehicle.
The electrical energy generated by the drive wheel motors/generators may be converted to heat in one or more dynamic braking resistor grids, and the heat is exhausted to the ambient by way of cooling air circulated through the resistive grids. During this mode of operation, the flow of cooling air may generate a significant amount of sound energy in the audible range. It is necessary and desirable to muffle that sound energy for the safety and comfort of the vehicle operator as well as reduce noise impact to the surroundings and also to comply with various regulations and vehicle specifications. Resistor grid silencing equipment must function to reduce noise emission while avoiding any impact on the efficiency of the heat dissipation from the resistor grids. In addition, such equipment must meet various dimensional constraints in order to meet operational and ergonomic considerations necessary for safe and efficient operation of the vehicle, such as providing an unimpeded view to the operator of a vehicle side mirror.